Drill bit



R. G. PETER June 5, 1956 DRILL BIT 2 Sheets-Sheet Filed Aug. 1, 1952Haber f 6. Fe 2 er INVENTOR.

ATTORNEYS June 5, 1956 I R. G. PETER 2,749,092

DRILL BIT Filed Aug. 1, 1952 2 Sheetg-5h61 2 fioberz 6. Pezer' INVENTOR.

gfIkH-M Jam -W DRILL BIT Robert G. Peter, Houston, Tex., assignor toReed Roller Bit Company, Houston, Tex., a corporation of TexasApplication August 1, 1952, Serial No. 302,211

3 Claims. (Cl. 255-415) This invention relates generally to drill "bitsand more in particular to means in roller bits for directing drillingfluid pumped therethrough.

In the drilling of deep wells, the drill bit is attached to the end of adrill stem and lowered to the bottom of the .hole. The drill stem isthen rotated causing the drill bit to penetrate the formation, anddrilling fluid is pumped downwardly through the drill stern and drillbit to remove cuttings dislodged by the drilling operation, and carrythem upwardly, in the space between the drill stem and the wall of thehole, to the-surface of the earth. Drill bits in common use .may beprovided with rollers to cut or crush the formation, and maybe providedwith nozzles to discharge drilling fluid toward the bottom of the holeso that cuttings or particles of formation dislodged by the bit duringthe drilling operation may be removed from the bottom of the hole. Incertain instances, the drill bit may become packed or bailed up when itis lowered by the drill stem to the bottom of the hole: that is, thecuttings dislodged by previous drilling operations, and other materialor detritus already in the -hole, may accumulate about the rollers andpack the drill bit as it is being lowered into the hole. As the drillingoperation progresses, the bit may 'ball up with cuttings at intervals,especi'ally'in the drilling of soft, sticky formations. Belling up ofthe drill bit may occur particularly in those roller bits 'in'which the"drilling fluid is discharged from the bit head and directed toward thebottom of the hole; accordingly, the fluid thus directed may not serveto clean properly the drill bit rollers and adjacent parts. As a resultof this, the rollers may .not freely rotate when the drill stem isrotated and the bit therefore does not efficiently drill the formation.

A general object of this invention is to provide a drill bit having newand improved nozzles which will serve not only to discharge fluid towardthe bottom of the hole but also to clean the bit of accumulated cuttingsand detritus.

Another object is to provide a new and improved bit in which thedrilling fluid pumped therethrough may be utilized alternatively toclean the drill bit and the bottom of the bore hole.

A specific object is to provide a new and improved fluid nozzle having afluid diverter adapted to divert fluid in accordance with the volume offluid passing through the nozzle in a given time interval.

Another specific object is to provide a new and improved drill bit fluiddirecting device wherein the device may be fluid operated so that fluidpumped therethrough at a relatively low velocity or pressure will bedirected to clean the bit, and fluid pumped therethrough at a relativelyhigh velocity or pressure will be directed to clean the hole beingdrilled by the bit.

Other objects and advantages will hereinafter appear from the followingdescription and the accompanying drawings wherein, by way ofillustration, this invention is set forth.

2,749,092 Patented June 5, 1956 In the drawings: v

Fig. -1 is a view taken along line l -r1 of Fig. 2.

Fig. 2 .is -a bottom :plan view of a drill bit showing an arrangement ofdrilling fluid nozzles in the drill bit.

Fig. 3 is a fragmentary sectional view showing schematically how thefluid diverter may divert fluid to clean the bit roller.

Fig. 4 is a fragmentary sectional view showing schematica-lly how thefluid .may be discharged downwardly.

Fig. 5 is a fragmentary view showing how the fluid diverter may beshaped.

Fig. 6 is a fragmentary view showing a modified fluid diverter.

Referring to Figs. v1 and 2, a drill bit is indicated generally by theletter A and the bit head is indicated at 1. The bit head 1 may haveoppositely disposed side roller bearing extensions 2 and oppositelydisposed cross roller bearing extensions 3. Side rollers 4 may berotatably mounted in the usual manner on the said side roller bearingextensions 2, and cross rollers 5 and 6 may be rotatably mounted in theusual manner on cross roller bearing extensions 3. The inner ends of thebearing extensions 2 and 3 may be secured to a bridge 7. The bit has athreaded shank 8 which is adapted to be connected to a drill stem (notshown). A drilling fluid nozzle 19 is disposed within the bore 10 of theshank 8, and has downwardly Ja'nd outwardly diverging fluid passageways11. The lower ends 12 of the nozzle 9 may be directed "to dischargedrilling fluid toward the bottom of the hole. A'wear resisting insert 13may be provided in the lower 'end 12 of the nozzle 9.

A fluid diverting device, indicated generally by the letter B, issecured to the nozzle end 12 by means of screws 14 'or any othersuitable means. The diverter B may be composed of a wear resisting plate15 "secured by brazing or other suitable means to a spring 16 which isattached to the nozzle end 12 as above described. The wear resistingplate 15 of the fluid diverter B is disposed in the path of the fluidbeing discharged from the nozzle ends 12 of the nozzle 9, and urged bythe spring 16 to a position substantially as shown in Figs. 1 and 3. Thefluid discharged from the nozzle ends 12 will thus imapinge the plate 15and 'be diverted thereby. Since the plate 15 is resiliently positionedby means of the spring 16 in the path of the fluid being discharged fromthe nozzle ends 12, the a'm'o'untoi fluid diverted by the diverter will-be inversely proportional to the velocity or pressure oflflu'idiimpingingthe said plate 15. That is; when drilling ifluid at arelatively low velocity or pressure impinges the :plate 15 a greateramount of the fluid will be diverted from its nozzle "directed course;but when fluid at a relatively high velocity or pressure impinges thesaid plate, the resistance of the spring 16 urging the plate 15 to theposition in the path-of the :fluid is overcome, and a relatively smalleramount of the fluid is diverted from its nozzle directed course.

Thus the diverter Bis adapted to permit the fluid being discharged fromthe said nozzle ends to clean the bottom of the hole being drilled bythe drill bit and is also adapted to divert a portion of the fluid beingdischarged from the ends 12 of the fluid nozzle 9, toward the rollers 4,S and 6 and toward the recess 17 above the said rollers to clean thedrill bit. The recess 17 above the rollers is formed by the lowerportion of the bit head 1; the lower portion 18 of the nozzle 9; theside roller bearing extensions 2; and the cross roller bearingextensions 3.

Fig. 3 shows schematically how the diverter B may act to divert drillingfluid to clean the drill bit rollers and adjacent parts, and Fig. 4shows schematically how a relatively higher velocity or pressure of thefluid impinging on the said diverter will cause it to open to a positionin which the flow of the fluid is substantially O unimpeded by the fluiddiverter, thereby utilizing the fluid to clean the bottom of the borehole.

Fig. shows the fluid diverter B wherein the wear resisting plate may beof a circular shape. 7 i

Fig. 6 shows a modification of the fluid diverter device wherein thelower end 12of the fluid nozzle 9 may have 9. lug 19 adapted to receivea pin 20. A wear resisting plate 15a, which may be a hard metal plate,is brazed or otherwise secured to one end of a torsion coil spring 21.The nozzle end 12 may have therein a socket 22 adapted to receive thefree end of the spring 21. The diverter device is mounted by insertingthe free end of the spring 21 into the socket 22; pin is then passedthrough the coil of the spring 21 and secured to the lug 19 in asuitable manner. The spring 21 urges the plate 15a substantially to theposition shown in Fig. 6. This diverter is similar in its operation tothe diverter B, hereinbefore and hereinafter described. 7

In operation, the drill bit A is secured, by means of the threaded shank8, to the end of a drill stem (not shown), which is then lowered to thebottom of the bore hole and rotated to cause the bit to penetrate theformation. During the lowering thereof, the drill bit may have becomeballed up" or packed, with cuttings standing in the hole, which havebeen dislodged during the previous drilling operations. The cuttings mayaccumulate about the side rollers 4 and the cross rollers 5 and 6 andespecially in the recess 17, thus balling up the drill bit before it isrotated on the bottom of the bore hole. Balling up or packing of thedrill bit may be so severe that the rollers may not turn freely, uponrotation of the drill stem, and thus may skid and be worn flat,materially reducing the useful life of the drill bit. Balling up of thedrill bit may occur from time to time as the drilling operationprogresses.

In order to alleviate this balling up" of the drill bit, I provide thefluid diverter B to divert drilling fluid, being pumped through thedrill stem and fluid nozzle 9, to clean the drill bit of the cuttingsand detritus which may have become packed therein.

After the drill bit has been lowered into the hole, the drillingoperator may cause fluid at a relatively low velocity or pressure to bepumped through the drill stem. The fluid then will impinge the diveterB, and a portion of the fluid will be diverted to clean the drill bit,as above described. After the drill bit is cleaned, the operator mayincrease the velocity or pressure of the fluid being pumped and proceedwith the drilling operation in the usual manner. The relatively highervelocity or pressure of the fluid impinging the diverter will cause itto become substantially inoperative to divert the fluid towards thedrill bit, and thus the fluid will be discharged substantially towardthe bottom of the hole to clean therefrom the cuttings dislodged duringthe drilling operation.

As the drilling operation progresses, the bit may again become balled upwith cuttings, causing the drill bit to penetrate the formation beingdrilled at a slower rate; whereupon, in formations where balling up ofthe drill bit is known to occur, the operator may reduce the velocity orpressure of the fluid being circulated so that the balled up bit may becleaned by diverting the fluid thereon in the manner above described;thereafter, normal drilling operations may again be resumed.

This invention is not limited to the embodiments shown. Various changes,within the scope of the following claims, will be apparent to thoseskilled in the art.

I claim:

1. A cross roller bit having a head, cross rollers and side rollersmounted in the lower portion of said head, a drilling fluid nozzlemounted in said head above said cross and side rollers and having itslower discharge end disposed adjacent to said rollers, and a fluiddiverter having a hard metal plate spaced from said discharge end andincluding means resiliently securing said plate to the lower end of saidfluid nozzle to cause said plate, when fluid issuing from said nozzle isdischarged thereagainst, to divert fluid against said rollers should theelocity or pressure of said fluid be relatively low, and to divert fluidto the bottom of the hole being drilled by said bit should the velocityor pressure of said fluid be relatively high.

2. A drill bit having a drilling fluid nozzle forming a part thereof anda drilling fluid directing device having a hard metal plate spaced fromthe discharge end of said nozzle and carried by means resilientlysecuring said plate to the lower discharge end of said nozzle anddisposed laterally across the path of drilling fluid issuing from saidnozzle, said fluid directing device being adapted to be actuated by thedrilling fluid issuing from said nozzle and discharging against saidplate to a position where it is not disposed across the path of thedrilling fluid when the fluid issuing from said nozzle has a relativelyhigh velocity or pressure whereby said drilling fluid is directeddownwardly to clean the bottom of the hole being drilled by said bit,said fluid directing device remaining in a position with said platedisposed across the path of the fluid issuing from said nozzle when thefluid has a relatively low velocity or pressure whereby said drillingfluid is directed in a manner to clean said bit.

3. A drill bit having a drilling fluid nozzle forming a part thereof anda drilling fluid diverter device having a hard metal plate spaced fromthe discharge end of said nozzle and carried by means resilientlysecuring said plate to the lower discharge end of said nozzle anddisposed laterally across the path of drilling fluid issuing from saidnozzle, said device being adapted to divert fluid issuing from saidnozzle to clean said bit should the velocity or the pressure of saidfluid impinging upon said plate be relatively low, and alternatively toclean the bottom of the hole being drilled by said bit should thevelocity or the pressure of said fluid impinging upon said plateberelatively high.

References Cited in the file of this patent UNITED STATES PATENTS2,238,895 Gage Apr. 22, l94l 2,335,929 Fortune Dec. 7, 1943 2,621,975Coles Dec. l6, 1952

